Antibiotics tetracycline adsorption and flame-retardant capacity of eco-friendly aerogel-based nanocellulose, graphene oxide, polyvinyl alcohol, and sodium bicarbonate

Abstract

This study presents a new approach in aerogel based on nanocellulose, graphene oxide, and its application as a novel adsorbent in water treatment and opening up a new potential material of thermal insulation. The eco-friendly aerogel materials were prepared by combining cellulose nanofibers (CNFs), graphene oxide (GO) sheets, polyvinyl alcohol (PVA), and sodium bicarbonate (NaHCO3) through a simple mixing and freeze-drying method. The structure of eco-friendly aerogel was also analyzed by scanning electron microscope (SEM) images, X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. The specific surface area and average pore diameter of the aerogel were also measured using Brunauer-Emmett-Teller (BET) analysis. The results showed that the presence of NaHCO3 played a role as a green flame retardant in CNF/GO/PVA/NaHCO3 aerogel. It significantly improved the thermal stability, 20 times higher in combustion characteristics, and thermal insulation efficiency better 3 times than those without NaHCO3. In addition, the NaHCO3 played as an effective additive to improve not only the thermal characteristics but also the removal ability of antibiotic TC of this aerogel material. The CNF/GO/PVA/NaHCO3 aerogel has the equilibrium TC adsorption capacity of 71.34 mg×g−1 which is about 28% higher than that of CNF/GO/PVA after approximately 60 min. The pseudo-second-order kinetic model showed an agreement with the adsorption model of this type of aerogel with a correlation coefficient (R2) of more than 99%.